Mold having compressible core.



No. 663,548. Patented Dec. I l, |900.

R. F. LUDLDW.

MOLD HAVING COMPRESSIBLE CORE.

(Application led Jan. 20, 1900.1

(No Model.)

w/TNESSES .I

Unirse Srarns ArnNr muon.

RODNEY F. LUDLOV, OF PHILADELPHIA, PENNSYLVANIA.

lVlOLD HAVING COMPRESSIBLE CORE.

SPIENQI TLFZUATION forming part of Letters Patent N o. 663,548,v datedDecember 11, 1900.

Application filed January 20, 1900. Serial No. 2,171. (No model.)

I To fl/Z when t 711,603/ concern:

Be it known that I, RODNEY F. LUDLOW, a citizen of the United States,residing at Philadelphia, in the State of Pennsylvania, have inventedcertain new and useful Improvements in Molds Having Compressible Cores,of which the following is a full, clear, and exact description,reference being had to the accompanying drawings, forming a part of thisspecification.

My invention relates generally to molds for forming metal castings, andspecilically to that class of molds employing compressible cores, andhas for its object to provide means for taking up or equalizing thestrain due to contraction of the cast metal on cooling.

To that end it consists of the combination 'with such a mold having asuitable mold cavity and recesses to receive the core and openings orpassages leading from such recesses of a compressible solid core.

The distinctive feature of theinventionnamely, the compressibility ofthe core and of minor features of novelt-y-Will be hereinafterdescribed,and pointed out in the claims.

In the drawings illustrating` my invention and how it may be carriedinto eifect, Figure l is a horizontal section of the drag or lower halfof the mold and of a compressible core therein. Fig. 2 is a verticalsection through both cope and drag on the line o: of Fig. l. Fig. 3 is avertical section on line w tu, Fig. 2. Fig. 4: is a like verticallsection on line c o, Fig. 2; and Fig. 5 is a like vertical section online ,a e', Fig. 2.

Referring to said drawings, the cope or upper half of the mold isindicated at M and the drag or under half is indicated at M in theseveral figures, and these views show also the relative arrangement tothe cope and drag of lthe compressible core and of the article cast inthe mold. In the several figures, A indicates the article cast; but ofcourse the shape will vary with the pattern of casting to be made.

B B B B B in Figs. l to 5 represent solid.

cores of compressible material hereinafter described, which fit into andtill openings T in the mold corresponding in shape thereto. Saidopenings communicate with other openings or pockets S S in both drag andcope of the mold, which openings or pockets S S preferably terminate inair-vents R, extending to the respective outer faces of the drag andcope, and hence when so constructed are open-ended; but it is obviousthat they may be located in any desired relation to the mold and at anyangle to the core and to the coreopenings in the mold. The solid cores Bare made of any of the well-known mixtures used for cores that willsoften rather than harden on exposure to the heat of the metal of thecasting when poured into the mold and which will be crushed on theapplication of pressure from the casting due to its contraction incooling. For this purpose I prefer to use a core, commonly called theoilcore, made of mixed sand and oil; but any other having thecharacteristics I have described above may be substituted with ,likeeffect in my in- Vention.

The operation is as follows: The compressible core B B' will be normallyhard in the cold and retain its solidity or normal shape long enough towithstand the molten metal poured in the mold until the casting coolssufliciently to take its intended permanent form, whereupon thecontinued heat 'of the casting will soften the solid core B and thepressure from the contraction of the casting in cooling will crush thesoftened core and force it or enough of it into the openings or pocketsS S of the mold to equalize the pressure and compensate for the strainthat would otherwise be attendant thereon.

I desire it to be understood that I do not confine my construction toany particular design of mold or core therefor, as these may be variedas occasion and particular construction of pattern or casting to be mademay require.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, is-

l. A mold for casting metal having a suitable inold-cavity,core-openings, and openings or pockets communicating with thecoreopenings, and an air-vent in communication with said openings orpockets, a compressible solid core composed of material that will initially withstand the heat of the molten metal until the casting sets,and will then soften on the continued application of heat from thelatter and be forced into said pockets by the IOO pressure of thecasting and thereby equalize and take up the natural strain produced bysuch cooling.

2. A mold for cast-ing metals having a suitable mold-eavity,core-openings, and open- ,ings or pockets communicating with the saidcore-openings, andma compressible solidleore composed of material thatWillinitially withstand the heat of the molten metal until the y castingsets and will then soften onthe continued application of heat from thelatter,

and be forced into said pockets by the pressure of the coolingcastingandthereby equalize andtake up the natural strain produced bysuch cooling.4 v

In testimony whereof I have hereunto affixed my signature this 12th dayof January,

iA'. D; 1900.1

RODNEY F. LUDLOW. Witnesses:

GEO. W. REED,- H. T. FENTON.

